Absorption refrigeration



2 Sheets-Sheet 1 Filed June 1, 1965 INVENTOR.

EVERETT Ff PALMATIER.

ATTORNEY.

Sept. 13, 1966 Filed June 1. 1965 2 Sheets-Sheet 2 1r N I I\- E w I CD g 7 q- 8 O m g co I m I go a I Q Hm 5 2| w h w :y

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wl I I Q! m I no m I N m g L I; INVENTOR.

I I EVERETT P. PALMATIER.

ATTORNEY.

United States Patent 3,271,976 ABSORPTION REFRIGERATION Everett P. Palmatier, Solvay, N.Y., assignor to Carrier Corporation, Syracuse, N.Y., a corporation of Delaware Filed June 1, 1965, Ser. No. 460,329 6 Claims. (Cl. 62-487) This invention relates to absorption refrigeration, and more particularly, to absorption refrigeration systems of the type which employ a pump for forwarding solution from the absorber to the generator of the system.

The design of a suitable pump for forwarding weak absorbent solution from the absorber to the generator of an absorption refrigeration system of the type which employs ammonia as a refrigerant and water as an absorbent, presents a number of special problems. In particular, typical head pressure requirements for such a pump substantially exceed that which can be satisfactorily achieved with a centrifugal pump. Vane and gear type pumps for this service would be required to operate at a high speed and could not be lubricated satisfactorily with water, and an oil lubrication system would be unsatisfactory due to emulsification of the oil with absorbent solution. They are also unsatisfactory due to cavitation, vapor binding and exhibit high rates of wear due to low lubricity of the solution being pumped and due to abrasive particles that cannot be entirely eliminated from the system. It is therefore desirable to employ a reciprocating pump for such application because they have a positive displacement and can operate satisfactorily to produce high head pressure at slow speeds where lubrication with water can be satisfactorily achieved.

In a typical air-cooled, ammonia-water absorption system, the high side or pump discharge pressure may be on the order of about 300 pounds per square inch gauge and the low side or pump suction pressure may be on the order of about 50 pounds per square inch gauge. During operation of the system, the internal pressures in the pump crankcase may be either above or below atmospheric pressure. On shutdown of the system, the system may typically equalize at a pressure of about 200 pounds per square inch gauge.

Since ammonia is toxic, it is necessary that the pump be fully hermetic and leak proof in spite of the wide variations in internal pressures to which it may be subjected. One approach to providing the required degree of leak tightness is to employ a so-called canned hermetic mot-or within the pump casing. However, this approach is not suited for relatively small size absorption refrigeration systems of the type which might be employed to cool a residence or small business establishment because of the cost of such an arrangement.

Absorption refrigeration systems, of the type described, normally utilize a fan for passing air over the evaporator and condenser. It would be desirable to use the electric motor driven fan to operate the solution pump. However, such an arrangement requires the use of a solution pump having an external seal because the fan motor must be outside the pump housing. The seal of conventional pumps is highly vulnerable to leakage and such pumps have provided unsatisfactory for the application described. For example, rubbing type seals always permit some small amount of leakage to occur which may become excessive in time, particularly in a system employing ammonia, where even a small amount of leakage is objectionable and where the internal pump pressure is substantially above atomspheric pressure on shutdown. Ela-stomeric seals have previously required bonding to the pump shaft and housing. However, it is virtually impossible to provide a satisfactory seal between an elastomeric seal member and a metal shaft or housing 3,2713% Patented Sept. 13, 1966 by the use of adhesives alone in an aqua-ammonia system, and clamped seals are difficult to retain in position due to the extremes in pressure to which they are sub jected in this application.

Accordingly, it is a principal object of this invention to provide an improved absorption refrigeration system of the type employing a solution pump.

It is a further object of this invention to provide an improved solution pump for use in absorption refrigeration systems, particularly of the ammonia-Water type, which is capable of being externally driven and which is adapted to operate without leakage over an extended period of time.

These and other objects of this invention are achieved in the illustrated preferred embodiment thereof by providing an improved reciprocating piston pump in an absorption refrigeration system for pumping weak solution from an absorber to a generator. The pump is provided with a power shaft extending through the pump housing. Linkage mechanism is provided to connect the power shaft with an electric motor which imparts an oscillating motion to the power shaft. The motor is preferably the same one which is used to drive a fan to pass air over the absorber and condenser. Suitable internal linkage is provided in the pump between the power shaft and the piston so that the oscillating motion of the shaft causes the piston to reciprocate within the cylinder to provide the desired pumping. An elongated, tubular, elastomeric seal bushing is clamped at one end thereof to the power shaft and at the other end thereof to the pump housing by suitable clamping rings. An internal support ring is disposed within the portion of the seal bushing exposed to ambient pressure to retain the seal in position and to prevent the collapse thereof due to high internal pump pressures, particularly upon shutdown, and the other end of the seal bush-ing is adhesively secured to the power shaft.

These and other objects of this invention will become more readily apparent with reference to the following specification and attached drawings wherein:

FIGURE 1 is a schematic diagram, partly in cross section of an absorption refrigeration system embodying this invention;

FIGURE 2 is a view, partly in cross section of a pump in accordance with the present invention; and

FIGURE 3 is a transverse view, partly in cross section of the pump illustrated in FIGURE 2.

Referring particularly to the drawings, there is shown in FIGURE 1 an absorption refrigeration system having an absorber 10, a condenser 11, an evaporator 12-, and a generator 13 connected to provide refrigeration. A pump 14 is employed to circulate weak absorbent solution from absorber 10 to generator 16. As used herein, the term weak absorbent solution refers to a solution which is weak in absorbing power, and the term strong absorbent solution refers to a solution which is strong in absorbing power. A suitable absorbent solution for use in the system described is water, and a suitable refrigerant is ammonia. For convenience, the absorbent liquid will be referred to as an absorbent solution although it will be appreciated that pure water is not technically a solution.

A chilled Water pump 20 is provided for forwarding water, or other heat exchange medium chilled in evaporator 12, through chilled water line 21 to heat exchanger 62 in a suitable remote location for chilling a refrigeration load. The water is then returned from heat exchanger 62 through chilled water line 22 to a spray header 19 from which it is again distributed over the exterior of evaporator coil 27.

Liquid refrigerant is passed from condenser 11 through liquid line 23, refrigerant rest-rictor 24, the exterior passage of liquid suction heat exchanger 25 and sec-0nd refrigerant restrictor 26, to evaporator coil 27 of evaporator 12. Heat from the water to be chilled, passing over the exterior of evaporator coil 27, is given up to the refrigerant which vaporizes in the interior passage of the evaporator coil. The refrigerant vapor passes from coil 27 through vapor line 28, the interior passage of liquid suction heat exchanger 25, to mixing line 29 where it is mixed with strong solution returning to the absorber from the generator.

The mixture of refrigerant vapor and strong solution passes through mixing line 29 into the heat exchange coil which forms absorber 10. Air is passed over the exterior of the absorber coil by fan 15 to cool absorbent solution therein and increase its absorbing power. The absorbent solution is weakened as it absorbs refrigerant vapor during its passage through the absorber. By the time the absorbent solution reaches the discharge end of the absorber coil, the refrigerant vapor is completely absorbed in the absorbent solution and the solution has become weak in absorbing power by the absorption of the vapor.

The weak absorbent solution passes through weak solution line 30 to a purge tank 31 where noncondensible gases are collected and withdrawn from the system. The weak solution is then forwarded by solution pump 14 through weak solution line 32 to combined rectifier and heat exchanger section 35.

Rectifier and heat exchanger section 35 comprises an outer shell 46 forming a vapor passage. Shell 46 con tains an inner heat exchange coil 45 and a concentric outer heat exchange coil 36, as shown in the drawing. Preferably outer heat exchange coil 36 is spirally disposed along the inner wall of shell 46 and it may be provided with suitable fins for enhancing heat transfer.

Coils 36 and 45 form a solution heat exchanger between the entire quantity of relatively hot strong solution passing from the generator to the absorber and the entire quantity of relatively cool weak solution passing from the absorber to the generator. The amount of heat transfer surface provided between the. strong and weak solution is designed so that the weak solution is brought to just about its boiling point so that vapor is not formed in the solution heat exchanger.

The weak solution from line 32 passes through coil 36 in the annular space between inner heat exchange coil 45 and outer heat exchange coil 36 where the Weak solution is heated to substantially its boiling point by heat exchange with strong solution. After passing through coil 36, the heated weak solution is discharged from opening 37 onto one of a plurality of battles or plates 39 in analyzer column 38.

Analyzer 38 comprises a tubular member having a plurality of plates 39 which provide surfaces for contact of vapor with the reflux and the solution which wets the surfaces of the plates. The weak solution passes successively over the plurality of plates and is dicharged from the bottom of the analyzer into a generator reservoir 40. Generator reservoir 40 provides solution storage for part load operation conditions and allows for solution and refrigerant charging tolerance, and compensates for manufacturing variations in machine volume.

Weak solution from generator reservoir 40 passes through line 49 into generator coil 50. The solution in coil 50 is heated by suitable means such as gas burner 51 causing the solution to boil thereby forming vapor. The vapor and hot solution is discharged from coil 50 into separation chamber 53, formed by a baffie or weir 52, where the vapor separates from the remaining strong solution. Preferably, some of the solution normally spills over the top of bafile 52 and is recirculated through line 49 to generator coil 50. It will be understood that the solution in separation chamber 53 has been concentrated by vaporizing refrigerant therefrom in generator 13.

Vapor formed in generator 13 passes concurrently with strong solution through the vapor passage 55 formed in the upper portion of generator reservoir 49, through analyzer 38, and through the vapor passage formed by shell 46 of rectifier 35 to condenser 11.

The concentrated or strong absorbent solution from separation region 53 is at the relatively high generator pressure and passes through heat exchange coil 48 in generator reservoir 49, heat exchange coil 47 in the analyzer column, and inner heat exchange coil 45 in the rectifer. The strong solution then passes through line 69 and restriction 61 into mixing line 29 and absorber 10 on the relatively low pressure side of the system.

Heat from the strong solution passing through coil 48 boils the weak solution in the generator reservoir to vaporize refrigerant therefrom. The heat exchange which takes place in the generator reservoir results in cooling the strong solution flowing through coil 48 so that it enters the analyzer and rectifier respectively at the best temperature to achieve maximum efficiency with minimum heat transfer surface.

A portion of coil 48 is submerged below the level of Weak solution in reservoir 40 and another portion of the coil is disposed in the vapor passage above the Weak solution. The boiling of the weak solution causes the portion of coil 48 which is disposed in vapor passage 55 to be Wetted with solution. As the strong solution passes through coil 48, it becomes progressively cooler. Vapor formed in the generator and in the reservoir passes through the vapor passage 55 and contacts the exposed and wetted portion of coil 48 in reservoir 40, and mass and heat transfer take place with the weak solution boiling in the reservoir. It will be appreciated that ammonia vapor will be boiled from the Weak solution in the reservoir and that water vapor will be condensed from the vapor space into the Weak solution in proportions resulting in an enrichment of the refrigerant content of the vapor passing through the reservoir. Also the condensation of Water vapor into the weak solution will liberate additional heat which assists in vaporizing the solution.

Similarly, as the vapor passes from the reservoir upwardly through analyzer column 38, a mass and heat transfer takes place between the weak solution passing downwardly over plates 39 in the column and further enriches the refrigerant content of the vapor.

The vapor then passes through rectifier 35 where it is placed in heat exchange relation with the weak solution passing through coil 36. The heat transfer which takes place in the rectifier results in condensing addition-a1 water from the vapor which then leaves the rectifier in a highly purified or enriched state.

The purified refrigerant vapor passes from rectifier 35 through line 58 into the coil of condenser 11. Fan 15 passes air over condenser 11 causing the refrigerant vapor to condense. The condensed refrigerant passes through line23 and restrictor 24 into evaporator 12, as previously explained.

As the vapor passes through rectifier 35, the reflux or solution which is condensed, flows by gravity to analyzer 38 and passes downwardly through the analyzer column along with weak solution discharged from outlet 37 of coil 36. This rectifier condensate is heated along with weak solution in the analyzer to produce additional vapor by heat exchange with strong solution passing through coil 47.

Pump 14 is shown in detail in FIGURES 2 and 3. The pump comprises a liquid-tight, hermetically sealed, housing 75 in which is formed a cylinder 77 having a piston 76 adapted to reciprocate therein. An intake valve 78 is connected to liquid line 30, and a discharge valve 79 is connected to liquid line 32. Reciprocat-ion of piston 76 in cylinder 77 causes weak absorbent solution to be withdrawn from the absorber through line 30 and discharged to the generator through line 32.

A rocker arm 80 is connected by a pin 81 to piston 76 through a piston rod. Pin 81 moves in a slightly arcuate path and there-fore a suitable flexible connection (not shown) is provided between the piston rod and the piston to accommodate changes in the vertical position of pin 81. Rocker arm 80 is secured to a pump power shaft 85 by means of clamping bolts 82.

Power shaft 85 extends through an aperture in the wall of housing 75 and is suitably journaled for oscillating motion therein. An external rocker arm 86 is secured to the portion of power shaft 85 extending out of casing 75 by a suitable clamping bolt 87. Casing 75 is provided with a pair of yoke arms 88 in which is journaled a rotatable drive shaft 89.

Drive shaft 89 carries thereon an eccentric pin 90 which is displaced from the axis of rotation of the drive shaft. Eccentric pin 90 is journaled in one end of link 91. The other end of line 91 is journaled by a pin 92 in the end of external rocker arm 86 which is remote from power shaft 85.

A pulley 84 is secured to drive shaft 89 and is driven by means of a belt from the fan shaft 16 which in turn is belt driven by electric motor 83. Electric motor 83 is preferably the same motor which is employed to drive fan 15 which passes air over condenser 11 and absorber 10.

In operation, motor 83 is connected by belts to pulley 84 in order to rotate drive shaft 89. Rotation of drive shaft 89 imparts eccentric motion to pin 90, which in turn causes link 91 to reciprocate. The reciprocating motion of link 91 causes a rocking motion of external rocker arm 86, which in turn imparts oscillating motion to power shaft 85. The oscillation of power shaft 85 causes internal rocker 80 to wobble, which in turn imparts reciprocal motion to piston 76 in cylinder 77. The reciprocation of piston 76 causes weak absorber solution to be pumped from absorber through lines 30 and 32 to generator 13.

As previously explained, the pressure Within the interior of pump housing 75 may be either above or below atmospheric pressure during operation of the absorption refrigeration system, and on shutdown, this pressure may exceed 200 pounds per square inch gauge. In order to prevent leakage of ammonia refrigerant out of the pump housing, a suitable seal arrangement is provided.

The seal arrangement comprises a hollow, tubular, flexible, impervious, preferably elastomeric, seal bushing 95 having a flange 96 at one end thereof. Seal bushing 95 is preferably made of a water resistant nitrile rubber. Flange 96 is clamped by means of a clamping ring 97 and clamping bolts 98 in a mating groove or recess formed between the exterior of pump housing 75 and clamping ring 97. Clamping ring 97 compresses flange 96 in liquid tight engagement with housing 75 and also retains bearing assembly 99 in position.

In order to prevent seal 95 from extruding excessively out of the groove formed between clamping ring 97 and housing 95, and to prevent the seal bushing from collapsing or being blown out of the groove by internal pressure, a support ring 102 is inserted into tight engagement with the interior of seal bushing 95 which is exposed to the ambient atmosphere.

The other end of seal bushing 95 is secured to the exterior of power shaft 85 by means of an external clamping ring 100. Assembling the seal bushing to the shaft, clamping ring 100 is tightly engaged over the exterior surface of seal bushing 95 and thereafter shaft 85 is driven into the seal bushing to form a tightly clamped assembly.

A drain 108 is formed in the upper portion of housing 75 so that when the pump is mounted at an angle as shown in FIGURE 1, a level of absorbent solution in pump 14 is established to contact and lubricate pin 81, piston 76 and the other bearings within the pump housing. A suitable drain line 109 is provided between drain 108 and liquid line 30 to conduct solution which bypasses piston 76 back to liquid line 30, thereby assuring that the pressure in housing 75 is at the relatively low absorber pressure.

It will be observed that the pump arrangement illustrated and described herein is fully hermetic and liquid tight so that ammonia or other toxic refrigerants employed in the refrigeration system do not leak from the pump housing. In operation, the ends of seal bushing rotate with respect to each other over the relatively limited range of motion of oscillating power shaft 85. The seal bushing is made sufliciently long so that the angle of deflection does not give rise to excessive stresses in the seal bushing, thus assuring long life. On the other hand, support ring 102 prevents collapse of the seal bushing when the refrigeration system is shut down and a large pressure difference may exist between the inside and outside of the pump housing. Since the ends of the seal bushing are clamped in liquid tight engagement with their respective parts, it is not necessary to rely on an adhesive bond to maintain tightness of the seal and the pump remains sealed from the ambient atmosphere for a long period of time without requiring service. The seal bushing remains fluid tight in operation because there is no rubbing connection between it and the power shaft or the pump housing during operation, thus eliminating a potential source of leakage and assuring a long, trouble-free life for the absorption refrigeration system.

While for purposes of illustration there has been described a preferred embodiment of this invention, it will be appreciated that the invention may be otherwise embodied within the scope of the following claims.

I claim:

1. An absorption refrigeration system comprising:

(A) an absorber for absorbing refrigerant vapor;

(B) an evaporator for evaporating refrigerant and providing a cooling effect;

(C) a generator for concentrating weak absorbent solution by vaporizing refrigerant therefrom;

(D) a condenser for condensing refrigerant vaporized in said generator; and

(E) a pump for passing absorbent solution in said system, said pump comprising:

(1) a pump housing containing a piston adapted to reciprocate within a cylinder to pump said weak solution;

(2) a power shaft extending through said housing and mounted thereon for oscillating motion;

(3) driving means for imparting oscillating motion to said power shaft about the axis thereof;

(4) linkage means within said pump housing connecting said piston with said power shaft for imparting reciprocating motion to said piston from the oscillation of said power shaft; and

(5) seal means for securing said power shaft in liquid-tight engagement to said housing while permitting oscillation of said shaft, said seal means comprising an elastomeric seal bushing,

said seal bushing being clamped in liquid-tight engagement with said pump housing and said shaft so that oscillation of said shaft is accommodated by a twisting movement of said seal bushing.

2. An absorption refrigeration system comprising:

(A) an absorber for absorbing refrigerant vapor;

(B) an evaporator for evaporating refrigerant and providing a cooling effect;

(C) a generator for concentrating weak absorbent solution by vaporizing refrigerant therefrom;

(D) a condenser for condensing refrigerant vaporized in said generator; and

(E) a pump for passing absorbent solution in said system, said pump comprising:

(1) a housing;

(2) a power shaft extending through said housing;

(3) driving means external of said housing to impart oscillating movement to said power shaft;

(4) a piston disposed to reciprocate in a cylinder within said housing;

() linkage means within said housing connecting said power shaft and said piston to impart reciprocating motion to said piston within said cylinder from the oscillating motion of said power shaft, for pumping weak absorbent solution; and

(6) a flexible, relatively imprevious seal disposed between said housing and said power shaft, said seal being clamped in liquid-tight engagement with said power shaft and said housing so that oscillation of said shaft causes a relative twisting of the seal while maintaining a liquid-tight engagement of said seal with the respective parts to which it is clamped.

3. An absorption refrigeration system comprising:

(A) an absorber for absorbing refrigerant vapor;

(B) an evaporator for evaporating refrigerant and providing a cooling effect;

(C) a generator for concentrating weak absorbent solution by vaporizing refrigerant therefrom;

(D) a condenser for condensing refrigerant vaporized in said generator; and

(E) a pump for passing absorbent solution in said system, said pump comprising:

(1) a housing;

(2) a power shaft extending through said housing;

(3) driving means external of said housing to impart oscillating movement to said power shaft;

(4) a piston disposed to reciprocate in a cylinder within said housing for pumping weak absorbent solution;

(5) linkage means within said housing connecting said power shaft and said piston to impart reciprocating motion to said piston within said cylinder from the oscillating motion of said power shaft; and

(6) a flexible, tubular, relatively impervious seal bushing disposed between said housing and said power shaft, said seal bushing being clamped adjacent one end thereof in liquid-tight engagement with said power shaft and being clamped adjacent the other end thereof in liquid-tight engagement with said housing so that oscillation of said shaft causes a relative twisting of the ends of said cylindrical seal while maintaining a liquid-tight, nonrubbing engagement of the ends of said seal with the respective parts to which they are clamped.

4. An absorption refrigeration system comprising:

(A) an absorber for absorbing refrigerant vapor;

(B) an evaporator for evaporating refrigerant and providing a cooling effect;

(C) a generator for concentrating weak absorbent solution by vaporizing refrigerant therefrom;

(D) a condenser for condensing refrigerant vaporized in said generator; and

(E) a pump for forwarding weak solution from said absorber to said generator, said pump comprising:

(1) a pump housing containing a piston adapted to reciprocate within a cylinder to pump said weak solution;

(2) a power shaft extending through said housing and mounted thereon for oscillating motion;

(3) means including an electric motor for imparting oscillating motion to said power shaft about the axis thereof;

(4) linkage means within said pump housing connecting said piston with said power shaft for imparting reciprocating motion to said piston from the lflfipll of said power shaft;

(5) seal means for securing said power shaft in liquid-tight engagement to said housing while permitting oscillation of said shaft, said seal means comprising a hollow, tubular, elastomeric seal bushing having a flange adjacent one end thereof, first clamping means disposed adjacent the other end of said bushing disposed to compress said bushing into liquid-tight engagement with said power shaft, second clamping means comprising a clamping ring disposed to compress the flange on said one end of said bushing into liquid-tight engagement with said pump housing, so that oscillation of said shaft is accommodated by a twisting movement of the ends of said seal bushing relative to each other.

5. An absorption refrigeration system comprising:

(A) an absorber for absorbing refrigerant vapor;

(B) an evaporator for evaporating refrigerant and providing a cooling effect;

(C) a generator for concentrating weak absorbent solution by vaporizing refrigerant therefrom;

(D) a condenser for condensing refrigerant \aporized in said generator; and

(E) a pump for forwarding weak solution from said absorber to said generator, said pump comprising:

( 1) a pump housing containing a piston adapted to reciprocate within a cylinder to pump said weak solution;

(2) a power shaft extending through said housing and mounted thereon for oscillating motion;

(3) means including an electric motor for imparting oscillating motion to said power shaft about the axis thereof;

(4) linkage means within said pump housing connecting said piston with said power shaft for imparting reciprocating motion to said piston from the oscillation of said power shaft;

(5) seal means for securing said power shaft in liquid-tight engagement to said housing while permitting oscillation of said shaft, said seal means comprising a hollow, tubular, elastomeric seal bushing having a flange adjacent one end thereof, first clamping means disposed adjacent the other end of said bushing for clamping said bushing to said power shaft in liquid tight engagement therewith, second clamping means comprising a clamping ring disposed to clamp the flange on said one end of said bushing into liquid-tight engagement with said pump housing, so that oscillation of said shaft is accommodated by a twisting movement of the ends of said seal bushing relative to each other; and

(6) a support ring disposed inside of said tubular seal bushing adjacent said one end thereof to retain said support bushing in engagement with said pump housing.

6. An absorption refrigeration system comprising:

(A) an absorber for absorbing refrigerant vapor;

(B) an evaporator for evaporating refrigerant and providing a cooling effect;

(C) a generator for concentrating weak absorbent solution by vaporizing refrigerant therefrom;

(D) a condenser for condensing refrigerant vaporized in said generator; and

(E) a pump for forwarding weak solution from said absorber to said generator, said pump comprising:

(1) a pump housing containing a piston adapted to reciprocate within a cylinder to pump said weak solution;

(2) a power shaft extending through said housing and mounted thereon for oscillating motion;

(3) means including an electric motor for imparting oscillating motion to said power shaft about the axis thereof;

(4) linkage means within said pump housing connecting said piston with said power shaft for imparting reciprocating motion to said piston from the oscillation of said power shaft;

(5) seal means for securing said power shaft in liquid-tight engagement to said housing while permitting oscillation of said shaft, said seal means comprising a hollow, tubular, elastomeric seal bushing having a flange adjacent one end thereof, first clamping means disposed adjacent the other end of said bushing for clamping said bushing to said power shaft in liquid-tight e-ngagement therewith, second clamping means comprising a clamping ring disposed to clamp the flange on said one end of said bushing into liquid-tight engagement with said pump housing, so that oscillation of said shaft is accommodated by a twisting movement of the ends of said seal bushing relative to each other;

(6) a support ring disposed inside of said tubular seal bushing adjacent said one end thereof to retain said support bushing in engagement With said pump housing; and

(7) drain means connecting the interior of said housing with said absorber to drain leakage solution from said housing and to maintain the pressure in said housing at substantially absorber pressure.

References Cited by the Examiner UNITED STATES PATENTS 2,929,222 3/1960 Lang 62-487 X 3,178,904 4/1965 Anderson 62-487 X 3,225,556 12/1965 Rohrs 6-2486 X LLOYD L. KING, Primary Examiner. 

1. AN ABSORPTION REFRIGERATION SYSTEM COMPRISING: (A) AN ABSORBER FOR ABSORBING REFRIGERANT VAPOR; (B) AN EVAPORATOR FOR EVAPORATING REFRIGERANT AND PROVIDING A COOLING EFFECT; (C) A GENERATOR FOR CONCENTRATING WEAK ABSORBENT SOLUTION BY VAPORIZING REFRIGERNAT THEREFROM; (D) A CONDENSER FOR CONDENSING REFRIGERANT VAPORIZED IN SAID GENERATOR; AND (E) A PUMP FOR PASSING ABSORBENT SOLULTION IN SAID SYSTEM, SAID PUMP COMPRISING: (1) A PUMP HOUSING CONTAINING A PISTON ADAPTED TO RECIPROCATE WITHIN A CYLINDER TO PUMP SAID WEAK SOLUTION; (2) A POWER SHAFT EXTENDING THROUGH SAID HOUSING AND MOUNTED THEREON FOR OSCILLATING MOTION; 